User`s manual

SBCSCSI/D1GL-1
Term Definition
CDB (NOTE) Command Descriptor Block - A defined SCSI structure used
to communicate commands from an initiator to a target.
DISconnect (NOTE) The function that occurs when an SCSI target releases control
of the SCSI bus, allowing it to go to the BUS FREE phase.
Initiator (NOTE) An SCSI device (usually a host system) that requests an I/O
process to be performed by another SCSI device (a target).
Logical unit (NOTE) A physical or virtual peripheral device addressable through a
target.
LUN (NOTE) Logical Unit Number.
MPU Microprocessor Unit (MC68040 on the MVME162, 166, and
167; MC88100 on the MVME187;MC88110 on the MVME197).
Nexus (NOTE) An SCSI bus relationship that begins with the establishment
of an initial connection and ends with the completion of the I/
O process. The relationship may be restricted to specify a
single logical unit or target routine by the successful transfer
of an "identify" message. The relationship may be further
restricted by the successful transfer of a queue tag message.
NVRAM The non-volatile RAM contained in the MK48T08 chip on the
Single Board computer (SBC). Also called Battery Backed-up
RAM (BBRAM).
Peripheral device A physical peripheral device that can be attached to an SCSI
device, which connects to the SCSI bus. The peripheral device
and the SCSI device (peripheral controller) may be physically
packaged together. Often there is a one-to-one mapping
between peripheral devices and logical units, but this is not
required. Examples of peripheral devices are: magnetic
disks, printers, optical disks, and magnetic tapes.
Reselect (NOTE) The SCSI function that occurs when a target selects an initiator
to continue an operation after a disconnect.
SCRIPTS NCR SCSI SCRIPTS code.
Glossary